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Re: An Option Towards Developing Treatment-Free Bees

WLC,Could you tell me whether you agree my distinction between stable local ecotypes that are 'hybrids', and 'mongrels'? If so, how would you place the dividing line between the two? Mike (UK)

Managed Honeybees aren't considered a stable ecotype. That would apply to local ferals. While there have been reports of reproductively isolated feral populations, as a general rule, ferals and managed bees are in disequilibrium. There will be introgression of alleles in either direction.

Yes, although I'm not sure that entails hybridisation - well mated within subspecies works just as well as far as I know.

I think it can only tell that there may be a fraction of the thing you fear - AHB genetics - that part responsible for WV pattern. I think you'd expect a lot of that in open mated queens from within the Texas hybrid 'survivor population', and there is no rationale for supposing that aggressiveness might accompany it.

It's not so much the aggressiveness. It's the other characteristics that make them challenging to work. As I've said elsewhere, I think that AHB drones mate earlier in the season than domestic ones do. I would expect to see that in a scatter plot of early vs late queens.

You would measure 'loss of hybridisation' by rising uniformity among workers? That may due to lower mating rates, or the presence of a stable survivor hybrid ecotype in NYC.

I'd measure that by comparing the before and after analyses. What stable ecotype in NYC? They're managed colonies that get replaced frequently.

What would qualify as a miracle?

Buying any old package bees, and having them actually survive.

You have to guard against undue aggressivness. So breed away when you see it.

How about I just order a new queen from BeeWeaver?

Eh? Geometric Wing Veination is a morphometric. ...?

They use a different method for determining AHB. But, it not the same as De Jong's method.

The problem here is that 'Africanised' is mumbo-jumbo. A scare-term. There's no such thing as an 'AHB.' There are hybrids with more or less African genetics, and that seems to roughly corrolate with aggressive behaviours. Fair do's. But finding a bit of African influence in a wing isn't a good reason to terminate the line.

Africanized is, unfortunately, very real. Some of their traits do seem to be dominant. There are some folks who do hive feral swarms. If they fit the AHB morphotype, you can't keep them. Some southern beekeepers were told that there are AHB around, but Darger has shown that they're some else, and that the test used returned false positives.

Re: An Option Towards Developing Treatment-Free Bees

Surely I think that would depend on who is doing the managing, where they got their bees, and how hard they work at keeping them pure. And who is doing the considering!

Originally Posted by WLC

That would apply to local ferals.

Originally Posted by WLC

While there have been reports of reproductively isolated feral populations, as a general rule, ferals and managed bees are in disequilibrium.

Are you talking about linkage disequilibrium? If so what does that mean for us?

Originally Posted by WLC

There will be introgression of alleles in either direction.

As far as I've seen (which isn't far) 'introgressions' refers to the insertion of alleles by repeated backcrossing into a pure strain. The commonly held notion of 'fixing' genes. So I'm struggling to see what you mean here.

Re: An Option Towards Developing Treatment-Free Bees

Surely I think that would depend on who is doing the managing, where they got their bees, and how hard they work at keeping them pure. And who is doing the considering!

If they're in a hive body, I would say no. If you're considering ferals found in the desert, forests, etc., it would apply. For example, Paul McCarthy has hived 'stable ecotypes' (ferals) from mountains in New Mexico.

Are you talking about linkage disequilibrium? If so what does that mean for us?

No, I'm referring to gene flow. For example, at one time, AHB genes were believed to be flowing into managed EHB stocks, one-way. Now we know that EHB genes have been flowing the other way as well including feral AHB colonies.

I'm not sure introgression is a usable idea outside of pure strains. In the feral and loosely managed populations there will be a spectrum of mash-up, with mongrels at one end.

It's an important issue, especially when dealing with AHB or resistance. It has to come from somewhere into managed colonies. So, if you open mate queens, you're hoping for an introgression of favorable alleles into your stock.

Now I really can't see what you are getting at .

You can get resistant colonies by hybridizing your non resistant stock with resistant ferals when open mating.

I've heard of a developing feral population, and wondered if it might have managed to find the sort of reproductive barrier we've been hearing about.

The Arnot forest 'survivors' are one example.

That's a big difference between us. Mine are in part the foundations of my future bees. I hope.

No, the big difference between us is that I can order bees from BeeWeaver. I think that since they're open mating in their location (Texas), it's a key to getting resistant colonies.

Mike (UK)

Sorry about replying within your quotes, but it's a bother to do otherwise.

As for hybrids vs mongrels: I would call the BeeWeaver queens hybrid Italian/Buckfast. However, once they're open mated in Texas, you could consider the resulting workers to be 'mongrels'.

Re: An Option Towards Developing Treatment-Free Bees

[MB] Surely I think that would depend on who is doing the managing, where they got their bees, and how hard they work at keeping them pure. And who is doing the considering!

If they're in a hive body, I would say no. If you're considering ferals found in the desert, forests, etc., it would apply. For example, Paul McCarthy has hived 'stable ecotypes' (ferals) from mountains in New Mexico.

Eh!!!! How does putting bees in a hive body make them stable ecotypes!

Originally Posted by WLC

[MB]Are you talking about linkage disequilibrium? If so what does that mean for us?

No, I'm referring to gene flow. For example, at one time, AHB genes were believed to be flowing into managed EHB stocks, one-way. Now we know that EHB genes have been flowing the other way as well including feral AHB colonies.

Why not say that instead of using technical terms wrongly?

Yes of course they've gone both ways. They've been mixing up, natural selection has been sorting out the best adapted combinations, and these are moving toward stable ecotypes where beekeepers can't screw up the process.

Originally Posted by WLC

[MB]I'm not sure introgression is a usable idea outside of pure strains. In the [unstable] feral and loosely managed populations there will be a spectrum of mash-up, with mongrels at one end.

It's an important issue, especially when dealing with AHB or resistance. It has to come from somewhere into managed colonies. So, if you open mate queens, you're hoping for an introgression of favorable alleles into your stock.

Again you are using this technical term in an inadequate way. Go back and see what I just said - 'introgression' refers to the 'fixing' of an outside gene set in a pure population as a result of repeated backcrossing (in one of the two parent races). As far as I can see - I may be wrong. You don't have that context. So you can't use that technical term.

Genes coding for resistance behaviours can be found in all populations. They are at a low level in the population unless circumstances have been such as to promote them - natural selection or beekeeper selection. Getting initial stocks with higher levels is great. Keeping them there by constant selective propagation is great. None of that amounts to 'introgression'.

'Introgression' of resistance genes, in the sense that they entirely replace alternative allelles would btw be a terribly thing. Your bees would be far too hygeinic.

Originally Posted by WLC

[MB]Now I really can't see what you are getting at .

You can get resistant colonies by hybridizing your non resistant stock with resistant ferals when open mating.

Yes, ok - though simply 'mating' is probably a better description. And you can lose it again just as fast through mating with treated bees....

Mike (UK)

The race isn't always to the swift, nor the fight to the strong, but that's the way to bet

Re: An Option Towards Developing Treatment-Free Bees

No Mike, Paul found stable ecotypes on the mountains of NM, then he put them in a hive.

No Mike, the fear was that AHB genes would swamp the genetic diversity of EHB colonies. Now we know that the flow has changed at the AHB front. In fact, in the South, it appears that AHB gene flow has been slowed down considerably by local feral/managed colonies to such an extent, that the flow may be going the other way.

Yes Mike, I can use the term introgression of alleles. Especially in the U.S. since AHB is an issue.

Re: An Option Towards Developing Treatment-Free Bees

Originally Posted by mike bispham

Again you are using this technical term in an inadequate way. Go back and see what I just said - 'introgression' refers to the 'fixing' of an outside gene set in a pure population as a result of repeated backcrossing (in one of the two parent races). As far as I can see - I may be wrong.

nothing to do with backcrossing and fixing. It is a straightforward term to describe when genes from one population get into the gene pool of another population. for example when Ligustica genes are found in an A.m.m. population.

Re: An Option Towards Developing Treatment-Free Bees

Originally Posted by Oldtimer

A citation to support that exists?

"We are now returning to our original goal of having queen producers and interested beekeepers select for this trait from among their own, tried-and-true stocks of bees. It is very important for beekeepers to have many stocks of bees to maintain a healthy level of genetic diversity [...] Fortunately, the hygienic trait is found in all races and stocks of bees."

That does only specifically cover the 'hygeine' traits as Marla Spivak understood them at the time of writing. Its been a fast moving field and there might be cautions to add.

Modifying my statement: there may be further behaviours, or capacities that are helpful to internal mite management that are less common. But at least some are found in all populations, according to this paper.

Mike (UK)

Last edited by mike bispham; 01-28-2014 at 03:00 AM.

The race isn't always to the swift, nor the fight to the strong, but that's the way to bet

Re: An Option Towards Developing Treatment-Free Bees

Originally Posted by jonathan

nothing to do with backcrossing and fixing. It is a straightforward term to describe when genes from one population get into the gene pool of another population. for example when Ligustica genes are found in an A.m.m. population.

I'm, learning as I go along, but I think my grumble is still there. The paper you reference talks about introgression of genes into pure race populations - its a study of the different degrees of introgression from apiary bees into a number of Amm ecotypes. The identified problem is that genes from apiary bees have entirely replaced the proper Amm genes - to varying degrees.

So the stable, pure race population has been compromised by introgression. The original genes are lost - if the same introgression occured in all Amm populations the original genes - a part of Amm would be extinct.

That is the significance of introgression.

What WLC describes is simple mixing, the creation of hybrids. And as you both point out, its gone both ways - well actually every which way. And no gene-sets have been lost, no part of any population has been made extinct. In theory at least natural selection still has all the resources it ever had to locate the best possible strains from the admixtures.

Only a pure race or ecotype can be introgressed in a strict sense. What WLC describes is just hybridisation, mixture. I think if you read the abstract of the paper you instance very carefully you'll see the difference.

Its often difficult to speak clearly about aspects of highly complex systems. This is an example - see below - I'm not the only one thinking this term is problematic:

"Introgression, a word often used in discussions of hybrid variation, has had various definitions. As originally defined by Anderson and Hubricht (1938: 396), it was the "infiltration of germ plasm from one species into another through repeated backcrossing of the hybrids to the parental species." This definition, however, is problematic because it involves the word species, which is not clearly defined. More recently, there has been an attempt to limit use of the term to situations involving permanent infiltration of genes from one population into another (Heiser 1973; Stebbins 1959). Thus, Rieseberg and Wendel (1993: 7) define it as the “permanent incorporation of alien alleles into a new, reproductively integrated population system,” But here, too, a problem arises with the definition of the term "integrated population system." There is also the problem of saying what constitutes "infiltration." In the case of many crosses, the genetic influence of natural hybridization is very local and affects only individuals in the immediate vicinity of the contact zone. In the case of others, the effect may be detectable hundreds of kilometers away. How should one draw a line between these two cases? What is "infiltration" and what is not?

In fact, the main difficulty with "introgression" is that it is thought of as an introduction of genes from one entity (usually thought of as a "species") into another. Actually, natural hybridization between two populations treated as species generally has a genetic effect only on individuals in the vicinity of the contact zone. No genes are introduced into other individuals elsewhere. Over the remaining geographic ranges of the two interbreeding populations, all individuals remain pure and genetically unaffected. The same distinction exists with the breeder's term introduction, the transfer of a trait via hybridization from a donor stock to a target stock. Here, the trait is introduced into only a subset of the target stock.

Indeed, the whole idea of introducing genes into a "genetic background" is probably misleading. In many cases, what is called "introduction into a target stock" is really crossing individuals of the target stock with individuals of some other type to produce hybrid individuals with genetic complements of mixed parental origin. Esuperanzi (2005: 302) suggests that birds produced by repeated backcrossing to a single parent should be regarded as belonging to that parental type only when they contain less than 1/16 blood from the other parent. But this is clearly arbitrary. Why not 1/8 or 1/32?

Even when the intention is to transfer a single gene to the target stock other genes often are transferred at the same time. For example, Carver and Taliaferro (1992: 131) note that even when the primary purpose is to transfer disease resistance to a crop, other traits, such as yield, may also be increased. If backcrossing occurs to one parental type or the other, the relative contributions of the two parents to the genetic complements of the resulting hybrids will vary in accordance with the amount of backcrossing that occurs. But no matter how many backcrosses to the target stock occur, so long as the traits of the offspring are discernibly mixed, they are hybrids, distinct from the target stock type.

For the foregoing reasons, the terms introduction and introgression, though widely used in the literature on hybridization, are avoided on this website."

Last edited by mike bispham; 01-28-2014 at 03:33 AM.

The race isn't always to the swift, nor the fight to the strong, but that's the way to bet

Re: An Option Towards Developing Treatment-Free Bees

More genetic diversity needed.........

Increasing Genetic Diversity of

Honey Bees--A Necessity, Says

Bee-Breeder-Geneticist

Susan Cobey

Dept. of Entomology
University of California at Davis
DAVIS--Increasing the overall genetic diversity of honey bees will lead to healthier and hardier bees that can better fight off parasites, pathogens and pests, says bee breeder-geneticist Susan Cobey of the University of California, Davis and Washington State University.

Just as stock improvement has served the poultry, dairy and swine industries well, the beekeeping industry needs access “to stocks of origin or standardized evaluation and stock improvement programs,” Cobey said.

Cobey is the lead author of the chapter “Status of Breeding Practices and Genetic Diversity in Domestic U.S. Honey Bees” of the newly published book, Honey Bee Colony Health: Challenges and Sustainable Solution.

“The many problems that currently face the U.S. honey bee population have underscored the need for sufficient genetic diversity at the colony, breeding, and population levels,” wrote Cobey and colleagues Walter “Steve” Sheppard, professor and chair of the WSU Department of Entomology and David Tarpy of North Carolina State University, formerly a graduate student at UC Davis.

“Genetic diversity has been reduced by three distinct bottleneck events, namely the limited historical importation of a small subset sampling of a few honey bee subspecies, the selection pressure of parasites and pathogens (particularly parasitic mites) and the consolidated commercial queen-production practices that use a small number of queen mothers in the breeding population,” Cobey pointed out.

The honey bee, Apis mellifera, originated in the Old World where it diverged into more than two dozen recognized subspecies, they related. However, only nine of the more than two dozen Old World subspecies ever made it to the United States and only two of these are recognizable today.

European colonists brought one subspecies, Apis mellifera mellifera or “The Dark Bee” of Northern Europe, to America in 1622, establishing it in the Jamestown colony. The bee was the only honey bee present in the United States for the next 239 years (1622 until 1861).

The Italian or golden honey bee, Apis mellifera ligustica, was introduced into the United States in 1859 and is now the most common honey bee in the United States. “Currently available U.S. honey bees are primarily derived from two European subspecies, A. m. carnica and A. m. ligustica,” the bee scientists said.

The U.S. ban on the importation of bees in 1922 to ward off a tracheal mite (Acarapis woodi) further aggravated the genetic bottleneck. Today the No. 1 enemy of the beekeeping industry is the parasitic Varroa mite (Varroa destructor), which has played a major role in the crippling decline of the U.S. honey bee population.

Found in virtually all bee colonies in the United States, it feeds on bee blood, can transmit diseases, and generally weakens the bee immune system.

What’s being done? “In the U.S. the recognized need to increase genetic diversity and strengthen selection programs of commercial breeding stocks has resulted in collaborative efforts among universities, government researchers, and the queen industry,” according to Cobey, Sheppard and Tarpy. “The current challenges facing the beekeeping industry and new technologies being developed are pushing beekeeping into a new era.”

To increase genetic diversity in the U.S. honey bee gene pool, Cobey and Sheppard are importing honey bee germplasm or semen of several subspecies of European honey bees and inseminating virgin queens of domestic breeding stock. They are also working on diagnostic programs to assist beekeepers to assess colony health and to evaluate commercial breeding stocks.

Cobey, who teaches queen-bee rearing classes and queen bee instrumental insemination at UC Davis and WSU, joined UC Davis in May 2007. Her research focuses on identifying, selecting and enhancing honey bee stocks that show increasing levels of resistance to pests and diseases. Cobey developed the New World Carniolan stock, a dark, winter hardy race of honey bees, in the early 1980s by back-crossing stocks collected from throughout the United States and Canada to create a more pure strain.

Sheppard , who leads the Apis Molecular Systematics Laboratory at WSU, studies population genetics and evolution of honey bees, insect introductions and mechanisms of genetic differentiation. His work was featured in a recent edition of the Washington State University Magazine.

Tarpy, now an associate professor and Extension apiculturist, at North Carolina State University, received his doctorate in entomology from UC Davis in 2000. He studied with Robert Page, emeritus professor of entomology at UC Davis who later became the vice provost and dean of the College of Liberal Arts and Sciences and Foundation Professor of Life Sciences, Arizona State University.
__________________

Re: An Option Towards Developing Treatment-Free Bees

Modifying my statement: there may be further behaviours, or capacities that are helpful to internal mite management that are less common. But at least some are found in all populations, according to this paper.

I would agree that hygienic behavior is found in all populations of bees. It is a general trait useful in prevention of brood disease. There should be a strong caveat that the trait is present in some populations at a higher frequency than in others. Italians for example have a relatively high level of hygienic traits where A.M.M. bees tend to have very little.

I would strongly disagree that this means that Varroa Sensitive Hygiene is found in all populations. The available evidence so far is that bees expressing very high levels of VSH also test as very highly hygienic, but that hygienic bees do not necessarily express VSH. In other words, you are stating that because A = B, of necessity B = C. You have not first proven that A = C. Either provide some evidence your statement is valid or else back off of it until you can prove it.

After 13 years of exposure to varroa and the death of most feral and many managed colonies in the U.S., I found one single colony that expressed moderately high varroa tolerance. The best I can estimate, 99.9% of our feral bees died up to that point. The only bees that remain from the original population are highly selected for traits that allow them to live with varroa. Unfortunately, this means that most of these bees swarm with an intensity never seen by me before. Serial swarming during summer allows multiple brood breaks which tend to reduce varroa pressure. Any varroa tolerance that relies on brood breaks to keep bees alive is fragile at best and will lead to compromised traits such as honey production.

There are three known mechanisms of varroa tolerance that do not rely on brood breaks. They are mite mauling behavior, varroa sensitive hygiene, and reduced days to worker maturity. VSH traits were present in Primorski bees to a high level as a result of 100 years of mite pressure. Both VSH and mite mauling are now present in feral colonies in the U.S. as a result of unrelentingly high selection pressure from varroa mites plus moderate levels of VSH genetics escaping into ferals.

Look for bees that survive and thrive in the presence of mites without expressing high levels of swarming. Don't hesitate to do what I did by purchasing some queens from a breeder who developed mite tolerant bees. The combination of traits from his queens and from my single queen gave me a very useful and highly mite tolerant line of honeybees.

Re: An Option Towards Developing Treatment-Free Bees

Originally Posted by Fusion_power

I would agree that hygienic behavior is found in all populations of bees. It is a general trait useful in prevention of brood disease. There should be a strong caveat that the trait is present in some populations at a higher frequency than in others. Italians for example have a relatively high level of hygienic traits where A.M.M. bees tend to have very little.

I agree. Of course those populations exposed for a longer period have better developed and better balanced defence mechanisms - and are, all else being equal, better candidates for starting stock. Russians are supposed to be still better equipped. In all cases mite management ability will likely vary - according to historic exposure and (more recently, and likely dramatically) the use of treatments in progenitor stocks.

Originally Posted by Fusion_power

I would strongly disagree that this means that Varroa Sensitive Hygiene is found in all populations. The available evidence so far is that bees expressing very high levels of VSH also test as very highly hygienic, but that hygienic bees do not necessarily express VSH. In other words, you are stating that because A = B, of necessity B = C. You have not first proven that A = C.

On second reading I think you're right:

"Hygienic bees detect, uncap, and remove diseased brood from the combs before the disease becomes infectious. Hygienic behavior also is one defense against Varroa mites (Peng et al., 1987), and although it is not the main mechanism of resistance to the mites (Harbo and Hoopingarner, 1997), it appears to limit their reproduction and population growth to some degree. Our studies have shown that it is possible to select for hygienic behavior without compromising honey production or gentleness (Spivak, 1996; Spivak and Reuter, in press). The trait can be found in approximately 10 percent of the managed colonies found in the United States, in any race or stock of bees." http://www.apiservices.com/articles/...iene_queen.htm

It seems likely that the specific intentions of the terms 'hygienic' and 'VSH' hadn't been separated out at the time this was written (the document is undated, but the latest reference is to a 1998 paper). The authors specify as follows:

"Although the common usage of the word hygienic denotes cleanliness, hygienic behavior is a specific response by the bees to diseased and parasitized brood. A colony that keeps its hive clean does not imply that it will be resistant to diseases. "

The authors go on to talk about the frozen brood assay for 'hygienic behaviour'. This test I agree doesn't specifically select for SMR/VSH.

Do you know of any studies that look at the specific issue of VSH across races and populations?

Its worth noting that only 1 or 2 patrilines need be SMR/VSH equipped in order for the colony to be resistant - and too many more would be damaging. It follows that not all i.e. Russions in a functional natural population are so equipped - just a sufficient proportion. The same must be true of US 'survivor' ferals.

Originally Posted by Fusion_power

There are three known mechanisms of varroa tolerance that do not rely on brood breaks. They are mite mauling behavior, varroa sensitive hygiene, and reduced days to worker maturity. VSH traits were present in Primorski bees to a high level as a result of 100 years of mite pressure.

There is also general resistance to the micro-oganisms that varroa creates vulnerability to. Grooming (auto and allo) without mauling may be separable behaviours. There may be others we don't know of. I don't necessarily agree that brood breaks are always a bad thing - breaks that are timed well with local flows might well be an advantage. The term 'brood break' might turn out to be a blunt instrument for what might be very nuanced and subtle responses to local environments, and we may want to speak more carefully about them. Of course those people who want mathematically programmed bees won't want anything to do with that kind of thing.

Originally Posted by Fusion_power

Both VSH and mite mauling are now present in feral colonies in the U.S. as a result of unrelentingly high selection pressure from varroa mites plus moderate levels of VSH genetics escaping into ferals.

It may be only the former reason. Genes coding for all kinds of mite-managment behaviours may well be present in all but the most narrowly diverse populations. I agree levels will be higher where mite exposure is longer (in ferals only).

Originally Posted by Fusion_power

Look for bees that survive and thrive in the presence of mites without expressing high levels of swarming. Don't hesitate to do what I did by purchasing some queens from a breeder who developed mite tolerant bees. The combination of traits from his queens and from my single queen gave me a very useful and highly mite tolerant line of honeybees.

That makes sense to me, but I'm increasingly thinking that possession of the right sort of mite in initial stocks would be a strong advantage too. A population of low fecundity mites supplies protection against a population explosion of flown-in mites from treated colonies.

Mike (UK)

Last edited by mike bispham; 01-29-2014 at 12:14 PM.

The race isn't always to the swift, nor the fight to the strong, but that's the way to bet